Plan three-
Using telepathic communications, aliens establish contact with all species of earth rodents, including mice, rats, squrriels, the IRS, etc... The rodents, on telepathic cue, infiltrate sensitive areas within major metro police and fire departments, NASA, military and intelligence installations, medical facilities and major communications networks. Once in place, the rodents gnaw through all console wiring including fiber optics and modem drivers for satellites systems, rendering both hard and soft communications systems useless.
Then, with the world's largest cities reduced to isolated islands of confused humanity, the invasion begins with a point by point systematic takeover of the entire planet.
Heaven help us!